Sewage disposal.



2 SHEETS-SHEET 1. 22*

R. W.'PRATT.

SEWAGE DISPOSAL.

APPLICATION FILED JUNE so, 1914.

' Patented Deo. 22, 1914.

R. W. PRATT.

SEWAGE DISPOSAL.

APPLIOATION FILED JUNE ao, 1914.

1,122,156. Patented De.22,1914.

R 2 SHEETS-SHEET Z.

inmensa.

ROBERT wINTHRor PRATT, OFCLEVELAND, oHIo. i

SEWAGE DISPOSAL.

Specication of Letters Patent. Patented Dem 22 1914:.

Original application filed March 16, 1914, Serial No. 824,910. Dividedyand this applicationv filed .Tune 30,

' 1914. Serial No. 848,184.

To all whom it may concern:

Be it known-that I, ROBERT W.PRATT, a citizen of the United States,residing at Cleveland, county of Cuyahoga, and State of Ohio, haveinvented certain newl and useful Improvements in Sewage Disposal, ofwhich the following is a specification.

In general the procedure which I propose may include the separating ofsand or other heavy mineral matter from the sewage as an initial step inits treatment. The sewage may be then passed through a sedimentationtank in which the sludge will separate out.

The sludge may then be passed into a chamber for further treatment whereit is heated so as to aid and hasten the bacterial action'. At this stepin the process a large portion of the sludge may rise to the surfacewhere it may be drawn off in a relatively dry state.-

The remainder of the sludge which settles to the bottom may be'drawn offand dried on drying beds or it may be mixed with the sludge which risesbefore being applied to the drying beds. It may be necessary to applythe sludge which rises, by itself and without admixture of the sludgewhich sinks, to the drying bed. The drying bed may consist of aninclosed chamber having a floor of sand on which the sludge is spread.Steam or other heating pipes may be embedded in the sand or may beplaced over the sand so as to be incorporated in the sludge itself ormay be arranged in the chamber above the sludge or elsewhere. Of coursehot air may be blown onto or drawn across the sandloeds` or they may beheated in any other way. The chamber containing the sand beds may beventilated in a satisfactorv manner and may preferably be provided witha transparent or translucent roof or sides or both andl tity of suchmatter often makes it desirable and economical to separate it from thesew age before the bacterial action takes place.

In most placesthe quantity of sewage to be treated varies from time totime and the result is that the speed with which the sewage passesthrough the receiving chamber varies, so that in order to insure themaximum amount of settling, means must be provided for 'maintaining thespeed of How .constant as the quantity varies. In one aspect myinvention accomplishes this. In the specific device illustrated, I haveprovided a trough through which the effluent from the sewer passes andwhich has sides adjustable to ward and from eachother so that the crosssectional area of the channel through which the sewage passes may bevaried. If the quantity of sewage increases the cross sectional area ofthe channel may be increased, thus equalizing the speed of flow or ifthe quantity of sewage decreases the sides may be adjusted toward eachother, thus diminishing the cross sectional area of the channel andequalizing the speed of iiow. The bottom of the trough is open so thatthe sand or other heavy mineral matter may settle into a receptaclebelow from which it may be -removed from time to time. next stepinvolves nothing new, but merely contemplates the passage of the sewageThe I through any known type of sedimentation tank in which the sludgeseparates out. The sludge thus procured is ordinarily spread upon dryingbeds and the bacterial action completed there. `I have found, however,that the sludge may be placed in a receptacle and heated toapproximately degrees F. This will produce, apparently, an immediatelyincreased and more or less violent bacterial action included in which isthe production of a large amount of gas which, being entrapped in thesludge, causes a portion thereof to rise to the top of the tank in aporous, and/fairly dry, spongy 'mass Moreover the entrapped gas, may becaused to expand by the heat and thus 'increase the tendency of thespongy mass to rise. In the particular structure shown in the drawings,I have provided means for heating the sludge in a chamber which has acontracted upper portion through which the spongy mass will be forcedonto a down- 7 wardly inclined draining shelf from which it may -beremoved from time to time.` In this spongy mass the bacterial action may-be entirely completed at this time and the mass withdrawn from thedrain board may be disposed of as is the sludge from the dryv ing beds.It may be desirable, however, to

time to time from Y ber. y

place the spongy mass for further drying v Y on'the ordinary drying bedsand it may be .The remnant of the sludge which does not so placed aloneor mixed with other, sludge.

risevas the spongy mass, must,.of course, be further dried-and may bewithdrawn from In ordinary practice, drying beds consist of surfacescovered with sand or other porous material on which the sludge may bespread and left in the open air to dry. In warm weather when there is norain and the sun shines daily, this final step in the f treatment of thesewage may be completed in a few weeks on the drying beds, but coldweather delays the processand rain delays the drying and addsmoisture tothe sludge, while dark eold days do not allow the bacl, terial action totake place so rapidly as in the sunshine.- I have found'that if meansare provided for regulating the temperature ofthe drying beds and forprotecting them against the inclemency ofthe weather with- J outdepriving them of light, the drying process may be reduced toa more orless sa' 'i tions the result being accomplished at times uniformoperation and considerable time saved during most of the year. Thismeans a large saving since it means that the acreage devoted to dryingbeds may be definitely calculated and limited. Ordinarily it isnecessary to let sludge stand for as much as three weeks on the open airdryingbeds. In some seasons it is sometimes necessary' to let the sludgestand Afor much longer times. This means that in arranging a sewagedisposal plant, a suiiicientv area of drying beds 4:5v mustbe providednot only to carry all the sewage that a city may have duringthree weeks,but considerably in excess thereof. By the'use of my drying beds thisnal'step in the treatment may be completed ina much shorter time despiteweather condi'- 1 in a few days so that such drying beds need Abeprovided for carrying the totalsew'age -for the correspondingly shortertime only. The'high cost ofland in the neighborhood ofthe large townsand cities makes this a matter of greateconomy. In the specific deviceshown `in the drawings, I have provided steam or other heating pipes soarranged as to regulate the temperature o f the sludge on the sand bedand I have provided a transparent or translucent cover lover the4 sandbed which will vprotect it from the weather. Means are provided 4forven-` tilating the `inclosed chamber and the light the bottom of thecham- Y may passxfto the sludge on the drying bed through the glass ortransparent or translucent cover.

The structures shown are satisfactory and ellicient, but my invention isnot limited to their details, but many other structures may be adoptedoradapted in accordance with my invention.l With this understanding, Iwill now proceed to describe the particular structures shown in thedrawings and how they may lbe used to carry out vmy invention.

Figure 1 isa diagrammatic sectional view of apparatus for treatingsewage and Flg.

2 is a sectional view through the receiving chamber.

The sewage, as received from the sewers is passed through the tank orchannel 1.

The sides 2 of the channel consist of inclined plates carried by runners3 which are engaged and operated by a chain 4 assing over wheels mountedon shafts 5. Any

suitable means, not shown, may be provided for rotating one or both ofthe shafts 5 to cause the sides 2 of the -channel to4 be moved toward oraway from each other. By this means the cross section of the channel maybe enlarged or decreased. Any suitable means for measuring the speed ofHow of f the sewage may be employed in the channel and when the speedchanges the adjustment of the sides 2 of the channel may be altered soas to keep the speed more or less con-` stant.

Of course, separatin the sides 2 of the channel will tend to reduce thespeed of flow of the sewage through the channel. I have foundthat if thespeed is 'kept low other heavy mineral matter carried by the sewage willbe deposited on the bottom of the chamber, passlng through the openingenough the greater portion of the sand or I between the bottomsl of thesides 2 of the channel. x If on the other hand the'speed of flow iskepthigh enough, substantially yall V lof the matter which is adapted tobacterial treatment will pass through the channel. If l.the speed -ofiowl is kept between these limits a separation takes place which greatlyreduces the amount of solid matter to be further treated and so tendstoward economy .and efficiency of the plant. From the channel 1 thesewage is passed throughsedimentation tanks- 6 of. any suitable type inwhich the sludge is separated out and settles to the bottom. In thediagrammatic scheme shown in Fig. 1 I have shown a series of pipes 7through which the sludge may be pumpedinto a channel 8 from which causesa portionof the sludge to rise to the surface in a more or less dryspongy mass Y in a relatively short time. This may be due provided withupwardly and inwardly in- 'clined sides 12 which force the rising spongymass up into the neck' or openingv 13 from which, at one side leads adownwardly 4inclined table 14 onto which the more for less vdry spongyportion .of the sludge is forced and from which it may be removed. anddisposedv of VVin any suitable manner. The-portion ofjthe sludge whichsettles to lthev bottom and remains in the chamber 10 may be pumped outthrough a pipe 15 anddelivered to sand beds 16 for further treatment.. v

I have s hown the sand beds provided with an inclosure 17 consisting ofa roof of glass rial and theside walls may also be 'of similar material.The :inclosure thus provided for-the sand beds may be fitted with heat-`ing pipes 18 located in the porous bedsunder the sand, andimmediatelyabove 'the sand so as to be covered by the sludge, and

also in the chamber 'above the sludge level.

0f course, theheating pipes in the. chamber above the sludge alone or ineitherone or in two of the locations might be employed, the intentionbeing to provide means for heating the sludge on'the sandfbeds. The.

inclosure may be ventilated and for this purpose, I.have.shown a fan 19situated in the side of the chamber to ,produce a forced draft, therevbeing an outletu-20 at the top of the chamber in which there may bealayer of deodorizing material 21; The

inclosure protects'the sludgel on the sand beds against `inclemency ofthe weather and availsof what heating comes from the sun .when itshines. Since -the cover allowslightf and heat of the sun to pass .tothe sludge a more satisfactory condition as regards bac-r terial actionis produced than will bepreskent on uncovered sandlbeds.

rAlthough I have shown a complete systo treat.l the spongy. massdelivered on to the inclined shelf 14; in similarly 'inclosed' sandbeds. Moreover,the chamber l0 may be used as an intermediate step in anysewage disposal process whether-the inal 'treatment is effected ininclosed sand' beds or not.

Of course, it will be understood that settling chambers 1 intermediatechamliers 10,

and inclosed sand beds may be employed of.

such sizeand in such 4numbers as are relquired by thev quantity ofsewage to be treated. .p

' Claims to thegapparatus 4shown in the drawings are not made in thisapplication `since it is intended to be covered bymy application SerialNumber 824910 led March 16, 1914 of which this is a division. I claim asmy invention:

1. In the disposal of- -sewage, passing it through an. unobstructedchannel, regucompleting the sludge treatment in a sand vided with altranslucent covering.

so l

`9o bed in a ventilated and heated` chamber pro- *or other transparentor translucent matei 2. In the disposal'of^ sewage, passing it throughan unobstructedchannel, regulating' I the speed of flow through theunobstructed channel, separating out the sludge, heating the sludge toseparate out a part of it in a -I more or less dry spongy mass, andcomplet- -ing the sludge treatment in a sand bed in a chamber ering. v

3. In the` disposal of sewage, assing-it through `an unobstructedchannel/regulatingithe speed ofiow through 'the' 'unobstructed channel,separating. out the'sludge, heating the sludge to separate out' apart ofit in amore or less dry spongy' mass, `and provided -with a translucentLcovcompleting the sludge treatment in'sa sand bed. A.

' 4. In the disposal of sewage, passing it through an unobstructedchannel, regulatstrueted channel, separating out the sludge,and-completing the sludge treatment in a 'ing the speed of flow throughthe .unob- 'Y sand bed in a ventilated andI heated cham- 115 berprovided with .a translucent covering.

.5. In the disposal of sewage, passing it tem of sewage disposal, theventire system need not `be"use`dl to come ywithin the scope of myinvention. The initial separation tank 1V may be used-as an initial,'step' in any mode vof treating sewage. The tank 10 may be applied to"sludge obtained in any way and whether it has sand radmixed with it ornot. In like manner the inclosed sand bed may be used either for sludgeobtained from the bottom -of the tank 10or in any other way and it mayat times `be desirable ing 'the yspeed of aow through the unobstructedchannel, separating out the sludge, and completing the sludge treatmentin a sand' bed ina chamber provided with a translucent covering.

6. In `the disposal of sewage, passing it throughan. unobstructedchannel, regulating the speed of flow through the unobstructedlchannel,,separating out the sludge,and completing the4 sludge treatmentin a sand bed.

' 7. In the disposal of sewage, separating out the sludge,hea ting thesludge to sepa,-

rate vout a partofit a more or less dry spongyv mass, and completing thesludge treatment ina sand bedin a ventilated and heated chamber;provided with a translucent covering.

' 8; .In the disposal of sewage, separating outthe sludge, heating thesludge to separate out apart of it in a more or less dry spongy'- mass,and completing the sludge treatment in a sand bed in a'chamber providedvwith a translucent covering.

9. In the disposal of sewage, separating" out' the sludge, heating thesludge'to separate.

out a part of it in a more `or less dry spongy mass, and completing thesludge treatment l f in a sand bed.

outvth'e sludge, and completing the sludge treatment in afsand bed in achamber provided with a translucent covering.

13. In the disposal of sewage, separating out the sludge, and completingthe sludge treatment in a heated sand bed.

14. As a=-step in the disposal of sewage, separating out the sludge, andheating the sludge to separate out apart of it in a more or less dryspongymass.

- 15. As astep in the disposal of sewage,

separatingout the sludge, and completing the sludge treatment in a sandbed in a ventilated and heated chamber provided with a translucentcovering.

16. Asa step, in the disposal of sewage,

y separatingout the sludge, and completing the sludge treatment in asand bed in a chamber provided with a translucent covering.

Signed at Cleveland, this' 24 day of June, 1914. l A R. WINTHROP PRATT.

IVitnessies KARL FENNING, FLORINE EVANS. v

